The present invention is generally directed to underwater diving, and more particularly, is directed to an underwater eardrum protector which protects scuba divers who have perforated eardrums. The device can also be used by individuals engaged in surface water sports (not more than about 30 feet of water depth) even if those individuals have healthy eardrums. The present invention serves to block water from entering into the auditory canal, a desirable result for individuals with healthy and damaged eardrums. As will be more fully explained hereinafter, the present invention should not be used by individuals with healthy eardrums at great water depths.
Current medical practice dictates that scuba divers should not dive to too great a depth if they have perforated eardrums, that is, ruptures or tears in their eardrums. This is because of the high water pressure which results in penetration by the water into the ear, causing permanent inner ear damage.
U.S. Pat. No. 4,406,282 to Parker et al discloses an earplug for an underwater diver. Specifically, the earplug includes a tubular bladder which is closed at its inner end and which is constructed of a soft, elastic-like material. Optionally, a set of filaments can be molded into the elastic-like material to allow radial expansion and inhibit lengthwise or axial expansion. This earplug is inserted into the ear and establishes an air pocket between the eardrum membrane and the end of the device. The air within the air pocket, as a result of the increased pressure on the eardrum due to deep diving in water, causes the flexible bladder to move, (See FIG. 5 thereof) to ensure contact between device and the middle ear's auditory canal.
The device of the '282 patent is not suitable for use by a diver having a puncture or tear in the eardrum. The present invention, in contrast, is primarily useful by those water divers having preexisting punctures or tears in their eardrum membranes. Also, in underwater diving situations, it is desirable that the user, as mentioned, having a preexisting eardrum puncture, be able to vary the pressure by the tubular bladder in the ear to a pressure different from that provided inclusively as a result of water pressure to ensure contact between the device and the auditory canal.
U.S. Pat. No. 3,505,999 to Harvey et al discloses an earplug having an expandable bag or balloon secured to a tube for selective insertion into the ear. A syringe or pump-like device serves to adjust the size of the balloon by adjusting the pressure on the fluid contained within the syringe and connecting tube. The pump-like device includes a cylinder having a fluid therein and a piston axially slidable within the cylinder for forcing the fluid through the tubing and into the expandable bag. A piston rod is fixedly connected with the piston for slidably moving the same within the cylinder.
In order to retain the piston in a desired depressed position, O-rings provide a tight fit between the piston and the interior wall of the cylinder. Accordingly, once the piston is moved to a depressed condition, thereby forcing the fluid from the cylinder through the hollow tube and into the expandable bag, and since the O-rings of the piston are in sufficiently tight frictional engagement with the interior wall of the cylinder, the piston will remain in such position. However, such tight frictional engagement between the piston and the cylinder so as to maintain the piston in its desired position causes extreme wear on the O-rings, thereby resulting in early failure of the device. Further, when performing underwater dives, the pressure within the ear may be sufficiently great to slidably move the piston out of the cylinder. The reason that no securing means is provided with this earplug is that it is designed to give protection against industrial noises and the like, that is, at atmospheric pressure. It is not intended for use at elevated pressures such as deep water diving.
U.S. Pat. No. 3,110,356 to Mendelson teaches an earplug having an ear insert member portion which has a canal or channel member and a flexible member in surrounding relation thereto. A sealed space is provided and bounded on the outside by the flexible member and on the inside by the channel member. A reservoir of liquid is provided for adjusting the size of the sealed space to thereby hold the earplug in position. Specifically, a tube connects the sealed space with the interior of a cylinder of the reservoir. A piston or plunger is slidably positioned within the cylinder. There is no specific description, however, of the relationship between the plunger rod and the cylinder of the reservoir. It appears from the drawing of FIG. 2 that the plunger rod is threadedly engaged with the cylinder. This would allow for the plunger to move in both directions as the turning screw is alternatively rotated in both directions. However, with such a relationship, rotation of the plunger rod to axially move the plunger or piston within the cylinder also results in rotation of the plunger itself. In the case where no O-ring is provided, a sufficiently tight fluid sealing arrangement cannot be provided, particularly in underwater diving situations. In the case where an O-ring is provided between the plunger and inner cylinder wall, there is an axial and rotational movement of the O-ring against the inner cylinder wall, resulting in relatively quick wear of the O-ring, and possibly early failure of the device, which can have disastrous consequences in deep underwater diving situations. In any event, the earplug of the 356 patent is designed specifically for above water, that is, atmospheric pressure, situations.
U.S. Pat. No. 2,876,767 to Wasserman discloses an earplug with an inflatable bladder which adapts itself to the contour of the ear canal. A syringe serves to adjustably provide pressure through a tube positioned within the interior of the inflatable bladder. However, there is no means to secure the plunger in a desired depressed position. Apparently, this occurs by means of friction between the plunger and the inner walls of the bore within which it rides.
Other similar, but less pertinent, devices are disclosed in U.S. Pat. No. 2,824,558 to Michael et al; U.S. Pat. No. 4,006,796 to Coehorst; U.S. Pat. No. 4,089,332 to Rose; U.S. Pat. No. 4,244,377 to Grams; U.S. Pat. No. 4,299,237 to Foti; and U.S. Pat. No. 4,060,080 to Akiyama.